Effects of psychiatric comorbidity on costs in patients undergoing disc surgery: a cross-sectional study

Abstract

Background context: Back pain presents a significant cause of health care costs and lost productivity. In most cases, conservative treatment will be sufficient, but in the most severe cases, disc surgery is indicated.

Purpose: To analyze the effect of psychiatric comorbidity on health care costs and lost productivity in patients with back pain undergoing disc surgery.

Study design: A cross-sectional study design was used.

Patient sample: A sample of 305 disc surgery patients (lumbar, 239; cervical, 66).

Outcome measures: Patients were interviewed using the German version of the Composite International Diagnostic Interview to assess psychiatric comorbidity and a questionnaire to assess resource utilization and lost productivity for a 3-month period prior disc surgery. Health care resources were monetarily valued by unit costs, whereas productivity was valuated by labor costs.

Methods: Cost differences between patients with and without psychiatric comorbidity were analyzed using bootstrap regression techniques.

Results: Back pain was associated with mean 3-month direct health care costs ranging from €5,534 (lumbar disc herniation without psychiatric comorbidity) to €8,507 (cervical disc herniation with psychiatric comorbidity), of which between 51% and 79% were caused by disc surgery. Mean indirect costs ranged from €7,589 to €8,492. Psychiatric comorbidity was significantly associated with increased direct costs in lumbar disc herniation (€7,042 vs. €5,534). Regression analysis showed increments of €851 (p=.043) in direct costs and €1,636 (p=.058) in total costs for psychiatric comorbidity, which predominantly resulted from nonpsychiatric health care utilization.

Conclusions: Severe back pain is associated with high direct and indirect costs, which are influenced by the presence of psychiatric comorbidity. We found a lack of treatment for psychiatric comorbidity indicated by low mental health care utilization in affected individuals. More attention should be given to psychiatric comorbidity in the treatment of patients undergoing disc surgery. Clinicians should be aware of the high prevalence rates of psychiatric comorbidity in this patient group. They should consider the assessment of psychiatric distress and support of mental health professionals if applicable.